forcats 1.0.0

New features

• New fct_na_value_to_level() and fct_na_level_to_value() to convert
  NA values to NA levels and vice versa (#337).

Minor improvement and bug fixes

• All functions now validate their inputs, giving more useful errors if you
  accidentally misspecify an input.

• fct_collapse() can now use other_level = NA (#291).

• fct_count() works with factors that contain NAs in levels.

• fct_explicit_na() is deprecated in favour of fct_na_value_to_level().

• fct_expand() gains an after argument so that you can choose where
  the new levels are placed (#138).

• fct_infreq() gains the ability to weight by another variable using the w
  argument (#261).

• fct_inorder() now works when not all levels appear in the data (#262).

• fct_lump_prop() and friends now work correctly if you supply weights
  and have empty levels (#292).

• fct_lump_n() and fct_lump_prop() will now create an "Other" level even
  if it only consists of a single level. This makes them consistent with the
  other fct_lump_* functions (#274).

• fct_other() no longer generates a warning if no levels are replaced with
  other (#265).

• fct_relevel(), fct_cross(), and fct_expand() now error if you name the
  arguments in ... since those names are ignored and your code probably
  doesn't do what you think it does (#319).

• fct_reorder() and fct_reorder2() now remove NA values in .x with a
  warning (like ggplot2::geom_point() and friends). You can suppress the
  warning by setting .na_rm = TRUE (#315).

• fct_reorder() and fct_reorder2() gain a new .default argument that
  controls the placement of empty levels (including levels that might become
  empty after removing missing values in .x) (#266).

• fct_unique() now captures implicit missing values if present (#293).